Australia is to send a group of 83 Sri Lankan asylum seekers to the tiny Pacific island nation of Nauru.
Australia has a camp for asylum seekers in Nauru
Immigration Minister Kevin Andrews said the move would send a strong message to prospective illegal immigrants.
But rights groups say that sending the group to Nauru will stop them from applying for Australian protection, and therefore breaches international rules.
Canberra had initially hoped to send the asylum seekers to Indonesia, but failed to reach a deal with Jakarta.
The 83 men were intercepted in international waters by the Australian navy last month, after setting sail from Indonesia.
Australian authorities have so far been holding the group on Christmas Island while they tried to reach an agreement for them to be returned to Indonesia.
But Australia failed to obtain Indonesia's guarantee that the asylum seekers would not be deported back to Colombo, so they were forced to find an alternative solution.
Keeping asylum seekers well away from the Australian mainland is part of a long-standing policy aimed at deterring boat people from arriving in the country.
"The government is committed to a strong border protection policy," Mr Andrews told reporters on Thursday.
"We are also committed to sending the strongest possible message of deterrence to people who would engage in the dangerous and unlawful activity of people smuggling," he said.
The offshore centre at Nauru was established in 2001 as part of Australia's tougher border protection regime.
The system, under which Australia pays the tiny country to keep asylum seekers in detention, has come under harsh criticism.
In 2001 a boatload of Afghan refugees was offloaded there, and human rights campaigners complained about the poor conditions in the camps they were kept in.
For some of last year the centre remained empty, but a group of Burmese asylum seekers were sent there last September.